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Growing trees in raised or above-ground containers, which are moveable, or planters, which usually are large, permanent fixtures, is an excellent way to bring greenery to a paved site, rooftop, balcony or other location where in-ground growing is not possible. Growing trees successfully in planters or containers requires choosing small species suited to confined spaces and suited to the amount of light available at the site. Then they need proper care.

Choosing the Right Trees

Certain tree species are more adaptable than others to living in planters. Small and dwarf species are obvious candidates because they don't need as much space for their roots to roam and won't grow as large as other varieties. Fruit trees, evergreens and Japanese maples all have dwarf cultivars. Other possibilities are smaller or slow-growing species, including dogwoods, crepe myrtles and magnolias. Then consider how much sunlight is available at the site you've chosen for the trees. Fruit trees generally need lots of sunlight to flower and fruit well while Japanese maples and dogwoods prefer light shade. Choosing an appropriate tree species will increase your chances growing the trees successfully.

Preparing the Planters or Containers

Each planter should be sturdy enough to contain the weight of the tree, soil and water. It also should be attractive and full of holes at the bottom to allow drainage when you water the tree. A container that will need to be moved should be lightweight, perhaps made of plastic or fiberglass, or placed on wheeled dollies. The potting mix to use depends on several factors. It needs enough body to stabilize a tree in a planter or container but not so heavy that one or more planters or containers filled with it will buckle the roof or balcony on which they rest. The potting soil also should not be heavy enough to make a planter or container designed to be moveable impossible to move. In general, soil-based potting mixes are heavier than soil-less potting mixes. Choose which to use according to your needs for the planters or containers.

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Minding the Temperature

Because their roots are exposed to above-ground temperatures on all sides and possibly heat reflected off pavement or walls, trees in planters are usually subject to greater temperature swings than trees planted in the ground. Lacking the protection they would receive in the ground, they may need to be placed in locations that are sheltered from wind and cold temperatures, such as next to a wall or in a courtyard, rather than in the middle of an open space. The larger the planter, the more the roots are insulated from temperature swings. If possible, provide 2 cubic feet of below-soil space for every 1 cubic foot of a tree's leaf canopy.

Watering and Fertilizing the Trees

Because trees in planters or containers must receive all their water and nutrients from a relatively small area of soil, they need more care than trees planted in the ground. Water them regularly and thoroughly, until water comes out of the drainage holes at the bottom of each planter. Fertilize the trees every year with a balanced fertilizer, or add fertilizer to their water at regular intervals. A balanced fertilizer has the same amounts of nitrogen, phosphorus and potassium, such as 10-10-10 fertilizer. Each spring, refresh the trees' potting soil by scooping out loose soil from every planter's or container's top and replacing it with fresh potting soil.

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About the Author

Emily Goodman is a writer and editor based in Brooklyn, N.Y. She has more than 15 years of experience as a journalist, writer and book editor. Also a trained gardener, Goodman's award-winning children's book, "Plant Secrets," was published by Charlesbridge in 2009.